With the expansion of oil production and transportation, there is increasing potential for oil spills from industrial accidents or sinking of oil tankers or ships. Conventional methods for removing oily pollutant from polluted water may include burning the oily pollutant, or using oil skimmers or oil absorbent material to collect (or to absorb) the oily pollutant. The conventional oil absorbent material, such as zeolites, kapok, activated carbons, silicas, organophilic clays, and synthetic polymer, is capable of absorbing the oily pollutant owing to the intrinsic absorption property thereof. However, the conventional oil absorbent material may suffer from some drawbacks such as relatively low absorption speed and relatively low oil-water selectivity. In addition, it is necessary to remove the absorbed oily pollutant from the conventional oil absorbent material by burning, by mechanical squeezing, or by solvent washing, which results in relatively high cost and relatively low efficiency for removal of the oily pollutant, and which renders the conventional oil absorbent material unable to be used for continuous removal of the oily pollutant from the polluted water.